ltr startin hard, and slow

[ltr450z]

my ltr is startin hard and i am not sure what it is? my best guess is it needs a top end.

and also my friends ltr has cams, pipe, intake, cherry bomb, new top end, power commander and it has no power its just always boggin. and u cant even do 2nd gear hole shots. my ltr with a pipe and power commander and cherry bomb is 15ft ahead by the time u hit 3rd gear, and they both have brand new 18in tires and same gearing. so what could it be?

[kfx400rider03]

the hard starting can be the valves. the other week my intake valves where messed up and wouldnt start unless i bumped started it but ran fine when it was running and yeah the valves being messed up made it lose some power